Alloy



UNITED STATES PATENT OFFICE.

ALVAH w. CLEMENT, or EAST CLEVELAND, omo, ASSIGNOR 'ro THE cLEvELANn BRASS MANUFACTURING co nrANY, or CLEVELAND, 01110, A oonroa OF OHIO.

ALLOY.

fie Drawing.

T 0 all whom it may concern:

Be it known that I, AnvAH W. CLEMENT, a citizen of the United States, residing at East Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Alloys, of which the following is a full, clear, and exact description.

Iron in the various forms in which it 1s commercially known and used is not effectively resistant to oxidization and warping when repeatedly subjected to heating's to" high temperatures, and iron containers, saggars, pyrometer tubes, and other structural formsv of iron when so repeatedly heated, deteriorate quite rapidly.

' Nevertheless, iron because of 1ts properties of easy machinability, ease of' casting and accessibility at comparatively low price, has been the metal chiefly used for such purposes before mentioned.

This invention has for its object, the provision of a metal'alloy which is highly resistant to oxidization and warping, and generally effectively withstands deterioration when subjected to repeated beatings to high temperature. Furthermore, the alloy is easily machined and may readily be cast.

The alloy of this invention includes as constituent elements, chromium, iron, silicon and aluminum, and optionally vanadium.

The chromium imparts to the alloy the property of resistance to warping even when repeatedly heated to high temperatures.

Silicon imparts to the alloy the property of resistance to oxidization when heated to high temperatures under oxidizing conditions.

Aluminum gives the metal a good grain structure.

Vanadium when used, increases the tensile strength although the alloy without the addition of vanadium is very satisfactory in this respect. 1

There is, of course, some carbon present in the alloy, and may be in the combined state as acarbid of iron and chromium, or it may be in the free state as graphitic carbon, or it may be present in both conditions.

If the allo in its use is to be subjected to fumes of sul urous or sulfuric acid, the alloy is more resistant to such fumes when the car- I bon is in the combined form. On the other Specification of Letters Patent.

Application filed July 21,

Patented Dec. 20, 1921'.

1917. Serial No. 182,005.

hand, the alloy is more resistant to the fumes of nitric acid or acids of this group, when the carbon is in the uncombined condition.

The proportions of the various elementary. constituents may vary, some within rather wide range, while others may not.

For instance. chromium when forming from 20% to 40% of the alloy, imparts to the alloy the propert of nonwarping at high temperatures. 7 owever, the most desirable and effective proportion of chromium is from 30% to 35% of the alloy.

Silicon is advantageously used only in small quantities, i. e. from 1% to 2%. Increasing the proportion of silicon makes the alloy more grainy, thus affecting the tensile strength and cross grain strength.

Aluminum is desirable only in small proportion from 1} of 1% to 1%. Aluminum is rather readily oxidizable, especially at high temperatures under oxidizing conditions.

The carbon content of the alloy is very low. In fact, it is made as low as possible, for the effect of the carbon is to work against the chromium and neutralizes its non-warpingvproperties.

The grain of the alloy is dense, and is not affected by flame.

The most important and dominant features of the alloy are those early mentioned in the specification, to-wit non-warpthe oxyhydrogen or oxyacetylene 'ing and resistance to oxidization when repeatedly heated to high temperatu'reseven under oxidizing conditions.

In speaking of high temperatures which the alloy may withstand, reference. is to' temperatures of from 2000 Fah. to'substantially 2500 Fah.

A notable feature of the alloy is that thin walled structures effectively withstand warping, so that light structures may be employed for any partlcular work, obviating clumsiness or excessive weight.

It will be clear from the foregoing that the fusion point of the alloy is quite high, and so far as known, only in the electric fur- .nace' can suflicient heat be gotten to produce fusion.

Having thus described my invention, what I claim is:

1. A metallic alloy which is substantially non-warping and resistant to deterioration when heated to high temperature containing iron, chromium in excess of 10% and a small quantity of siliconand aluminum.

2. Ametallic alloy which is substantially non-warping and resistant to deterioration when heated to high temperature, containing essentially iron, chromium in excess of 10% and another substance having the properties of silicon which resists oxidization at high temperature. v

3. A metallic alloy whichis substantially non-warping and resistant to deterioration when heated to high temperature containing essentially iron and chromium in excess of 10%, and a sufiicient amount of silicon to resist oxidization at high temperature.

4. A metallic alloy which is substantially non-warping-and resistant to deterioration when heated to high temperature containing essentially iron and chromium in excess of 10%, and not more than 2 per cent. of silicon and not more than 1 per cent. of aluminum.

5. A metallic alloy which is substantially non-warping and resistant to deterioration when heated to high temperature containing essentially ironand afsmall quantity of chromium, in excess of 10% silicon and aluminum, and less than 1 per cent. of carbon.

6. A metallic alloy containing 20 to 40 per cent. of chromium, 1 to 2 per cent. of

silicon, to 1 per cent. of aluminum, and the remainder iron. v

7. A metallic alloy containing 20 to 40 per cent. of chromium, 1 to '2 per cent. of-

silicon, to 1 per cent. of aluminum, substantially of 1 per cent. of vanadium, and

the remainder iron.

In testimony whereof, I hereunto afiix my signature.

I ALVAH W. CLEMENT. 

